The AUSubaru.com.au Forums

I am again looking at the possible upgrade of the 'power pipe'

What size pipe do I go?

Factory is like 1.25in on the straight & 1in on the bends.

Is 1.75in on the straight & 1.25 on the bends too big?

Any comments would be appreciated

Thanks - Justin

Are you a member of the USMB?
Ive seen a few on there, TWE come to mind
I will see if i can find some pics

think I posted these ages back on old forum.

if you' chasing power, something like this is the best thing since sliced bread. Prettymuch mandatory really, not just bigger pipes, but the merging design.

I had alll sorts of troubles with the stock pipes, it was extremely obvious they were trouble on the dyno as they would glow bright red when trying to tune.





only thing I can't remember is the size, i'd have to get in there with some calipers. since that's your main Q afterall.

-ed oh and to give some indication of how effective they were, before, it was probably a 16sec car at best, and winding the boost up to 15 would do nothing.

after, It ran an easy 15.1 @ 90mph prettymuch straight after installing them and getting engine back in, with just basic road tune, heat soak mania top mount, and about 11psi . I still havent been back since adding a fmic and more boost .. been nearly 2 yrs now :/

Thanks for the pic, that front pipe on mine is leaking so I want to get it off to make a jig for exactly what you have shown.
All I need is some bends, a mig and some time.
The "T" join from the RHS header on the original would be the most crudest design I have seen.

Would there be any point in butchering a EJ20T original header for these bends, anyone see reason to this?

mAJORD Thanks for the pics they are a great help!

So you are not to sure on the size?

I still want to retain the VF2 that is currently on the car so it boosts very early in the rev range.

I like your enginuity here, heh and the use of surgical gloves to stop foreign objeks entering orifices !

Do you loose the subaru note because you have changed the lengths?

These are two types ive seen
The techworks kit was a group buy on the USMB i think
The other 3 pics are of a home made job that an american guy made out of stainless steel. I would seriously put my money on this design
He has obviously put some time into his design





Yes you would change the subaru note (Boxer Rumble) if the pipes were the same length. I made some equal lenght headers for my carb ea28 and it lost its subaru sound completly. I went back to unequal lenth headers cos i love that sound.

I dont think that equal length pipes are the key, its the merging of the two pipes.

The guy from the USMB that made the stainless steel crossover goes by the name of "Boosted Balls".


Gannon

jono - works a charm!

schulzie, like suba said, not unless you make them equal length. Mine is more boxer sounding / rex sounding than before, losing most of the 'tractor sound' associated with that motor, and sounding more like a rex instead.

might have to play with this idea, what is the go with the size then, would 1.75 be to big or is 1.5 more likely to have an inproovement over the standart 1.25 and then not cause to muc of a loss in back pressure, how about boost have younoticed it come on slower?

sorry xtreme, somehow missed your post there

the pipe size is:

just shy of 1 3/4in OUTSIDe diameter

merging into a 2.5inch OUTside dia pipe up the turbo.

so not certain what i/d would be but someone who knows what sort of pipe the exh probably used for such a task might know the wall thickness.

it's a VF12 though, so if you're not going to replace the std little huffer then I'd go a bit smaller to keep the gas velocity up, etc etc. I have no way of telling if it spools up slower / later with them as the turbo is bigger, hence it is slower to spool anyway.

What would be the going rate to have headers like that built by an exhaust place?

they only cost me about 250, but I was expecting it to be more.

this was from noyzworx in bris which I think are no more?

they've done awesome work at good prices on a few things now. They did exactly what I needed in this case, without hassle.

Thanks to all who replied. Now I have some serious ideas!

Another saleable item for black box motorsports maybe ?

Does anyone have pic of what the factory item looks like out of the engine bay?

the factory turbo crossover pipe you mean ?

nuh !

but can do if you need

jono wrote:the factory turbo crossover pipe you mean ?

nuh !

but can do if you need

Yeah the factory crossover pipe.
Is your engine out at the moment so you can take a good pic of it? I just want to get the two pics together to compare the difference.

OUT ?? Yeah, I am still waiting for the donor donk stuck on someones farm *cough*cough

just put batteries on charge, meanwhile use your imagination...pipe exits at a right angle out of LHS head and goes forward and just wraps around engine travelling past RHS head going up to turbo. RHS feeds a T junction to this pipe. Thomas, you must have a bloody dirty donk not to see this on your own, considering you have spent time underneath your beast !

PM me your email addy and I will send of a low KB pic when batteries have charged up

Jono

I Can see mine just fine, but lying on your back under the car is not nearly has helpful as seeing the whole thing nice and clean and out of the engine bay:rolleyes: . I was just hoping someone would have a similar picture (to picture mAJORD put up) of the factory item.

I have had a look recently and have been wondering about just redoing the part were the left and right side merge together rather than making a whole new crossover pipe system, to get better flow through there.